Great recipe! I made my own blueberry pie filling using Kittencal's Blueberry Pie (Option for Freezing), then scooped out 21 ounces for the jam. It was heavenly. Also, I reduced the sugar down to 4 cups and it was still plenty sweet. We all loved it & will totally make it again.
Never really thought blueberries and rhubarb went together but it made for a intresting mixture.Thanks.
Too sweet for me and don't really taste the rhubarb but the plus side was that it was easy to make.